1. Field of the Invention
This invention relates to methods and apparatus for wrapping strands on articles, and more particularly, to methods and an improved wire wrap bit for wrapping the ends of electrically conductive wires on metallic terminals.
2. Description of the Prior Art
Wire wrapping tools conventionally include a rotary driver for rotating a bit which is disposed within a stationary sleeve member. The bit has a central axial recess at one end to receive a terminal and a radially offset longitudinal channel or slot to receive the bare wire or shiner to be wrapped about the terminal. The wire outside the channel is anchored to the sleeve member and upon operation of the rotary driver, the bit is rotated and the wire is withdrawn from the channel as it is wrapped about the terminal.
In order to form a desirable tight wrap, the channel has a diameter only slightly greater than the diameter of the wire. This causes tension in the wire as it is withdrawn from the channel due to the frictional drag on the wire as it is being wrapped. Because of the close tolerances between the wire and the channel surface, such a prior art wire wrap bit is normally limited to accepting only a single gauge of wire and poses substantial difficulty to the operator when inserting such a wire to be wrapped into the opening of the channel. In addition, with extensive use, the channel tends to enlarge due to wear thereby producing a loose fit between the wire and the channel surface, reducing the frictional drag. This tends to decrease the tension on the wire as it is being wrapped, resulting in unacceptable loose wire wraps.